Abstract:
Optical switches and logic devices comprising microstructure-doped nanocavity lasers are described. These switches and logic devices have gain and thus can be cascaded and integrated in a network or system such as for example on a chip. Exemplary switching elements switch the intensity, wavelength, or direction of the output. Exemplary logic devices include AND, OR, NAND, NOR, NOT, and XOR gates as well as flip-flops. Microfluidic sorting and delivery as well as optical tweezing and trapping may be employ to select and position a light emitter in an nanooptical cavity to form the nanolaser.
Abstract:
Systems and methods for manipulating light with tunable ferroelectric photonic devices. Devices having tunable properties that exhibit photonic bandgap behavior are fabricated from ferroelectric materials. Apparatus is provided to apply tuning signals to the ferroelectric material using one or more of electric fields, mechanical forces, optical fields, and thermal fields. Control circuitry is provided to generate the control signals needed to apply the tuning signals. Input and output ports are provided to allow input signals to be received and to provide output signals. In some cases, a feedback loop is provided to use a portion of the output signal as a diagnostic signal for control of the operation of the device within an acceptable range. It is expected that ferroelectric photonic devices operating according to principles of the invention will be useful for a wide variety of applications, including optical switching, optical modulation, optical computing, and performing logic optically.
Abstract:
Systems and methods for obtaining two- and three-dimensional magnetic resonance images by using azimuthally symmetric dipolar magnetic fields from magnetic spheres. A complete two- or three-dimensional structured rendering of a sample can be obtained without the motion of the sample relative to the sphere. Magnetic spheres in the range of 100 μm and 100 nm are used with samples that are approximately one-tenth as large as the magnetic sphere. Sequential positioning of the integrated sample-sphere system in an external magnetic field at various angular orientations provides all the required imaging slices for successful computerized tomographic image reconstruction. The requirement to scan the sample relative to the magnetic tip is eliminated. Resolutions approaching atomic dimensions are expected to be obtained.
Abstract:
A method of fabricating an elastomeric structure, comprising: forming a first elastomeric layer on top of a first micromachined mold, the first micromachined mold having a first raised protrusion which forms a first recess extending along a bottom surface of the first elastomeric layer; forming a second elastomeric layer on top of a second micromachined mold, the second micromachined mold having a second raised protrusion which forms a second recess extending along a bottom surface of the second elastomeric layer; bonding the bottom surface of the second elastomeric layer onto a top surface of the first elastomeric layer such that a control channel forms in the second recess between the first and second elastomeric layers; and positioning the first elastomeric layer on top of a planar substrate such that a flow channel forms in the first recess between the first elastomeric layer and the planar substrate.
Abstract:
A method of fabricating an elastomeric structure, comprising: forming a first elastomeric layer on top of a first micromachined mold, the first micromachined mold having a first raised protrusion which forms a first recess extending along a bottom surface of the first elastomeric layer; forming a second elastomeric layer on top of a second micromachined mold, the second micromachined mold having a second raised protrusion which forms a second recess extending along a bottom surface of the second elastomeric layer; bonding the bottom surface of the second elastomeric layer onto a top surface of the first elastomeric layer such that a control channel forms in the second recess between the first and second elastomeric layers; and positioning the first elastomeric layer on top of a planar substrate such that a flow channel forms in the first recess between the first elastomeric layer and the planar substrate.
Abstract:
The development of a high-throughput multi-antigen microfluidic fluorescence immunoassay system is illustrated in a 100-chamber PDMS (polydimethylsiloxane) chip which performs up to 5 tests for each of 10 samples. Specificity of detection is demonstrated and calibration curves produced for C-Reactive Protein (CRP), Prostate Specific Antigen (PSA), ferritin, and Vascular Endothelial Growth Factor (VEGF). The measurements show sensitivity at and below levels that are significant in current clinical laboratory practice (with SIN>8 at as low as 10 pM antigen concentration). The chip uses 100 nL per sample for all four tests and provides an improved instrument for use in scientific research and “point-of-care” testing in medicine.
Abstract:
A method for fabricating parylene coated microfluidic valves is disclosed. A three-dimensional mold made of a first wax is formed. A sacrificial material made of a second wax is provided as a temporary support and then dissolved. A parylene coating is deposited onto the mold. A component material is poured onto the mold and cured, and the first wax is melted away. Further, a method for parylene coating of two-dimensional microfluidic components comprises: forming a lithographic mold of a microfluidic component, the mold made of a photoresist material; coating the lithographic mold with parylene; and removing the lithographic mold.
Abstract:
The invention is directed to different methods for controlling the positions of the guided modes of the photonic crystal waveguides. Methods based on both rearrangement of the holes and changing the size of the holes are presented. We have observed and explained the appearance of acceptor-type modes and the donor-type waveguides. The ability to tune frequencies of the guided modes within a frequency bandgap is necessary in order to achieve efficient guiding of light within a waveguide (reduced lateral and vertical waveguide losses) as well as to match frequencies of eigen modes of different photonic crystal based devices in order to have good coupling between them.
Abstract:
A strip loaded waveguide comprises a slab and a strip, wherein the strip is separated from the slab. Nevertheless, a guiding region is provided for propagating an optical mode and this guiding region extends both within the strip and the slab. A layer of material having an index of refraction lower than that of the strip and the slab may be disposed between and separate the strip and the slab. In one embodiment, the slab comprises a crystalline silicon, the strip comprises polysilicon or crystalline silicon, and the layer of material therebetween comprises silicon dioxide. Such waveguides may be formed on the same substrate with transistors. These waveguides may also be electrically biased to alter the index of refraction and/or absorption of the waveguide.